This invention relates generally to methods of growing plants in a closed environment, such as a nursery, and more particularly to an apparatus which enables more efficient utilization of the enclosed volume found in nurseries.
There are three normal methods of growing containerized plant material, these include placing it on the ground, benching it, or placing it on stair step structure. The on the ground system is where the plants are actually placed on the bare earth or on a type of ground cover that inhibits weed growth. When plants are placed above ground level it is usually on a bench system. This consists of a frame covered with wood, or other suitable material that allows the container to rest on a flat surface. An alternative to this type of bench system is the placement of strips of wood across the bench spaced at intervals that allow the pots to fit between the wood strips which are nailed to the frame. The third growing system is the stair step method; here two sets of stairlike structures are set opposing each other so that the highest platforms are together in the center. This gives a step-up effect from two sides and meeting in the middle.
There are certain drawbacks and advantages to each system. The obvious advantage of the "on ground" method is the low ingoing costs. There are, however, increased costs in production such as increased fuel consumption, unfavorable plant environment, less productive work conditions and additional weed control cost.
The bench system takes the plants off the ground and therefore provides a better environment for healthy growth. This improved environment is at the expense of space utilization since more aisles are required creating more unproductive area. Though the benches are more sanitary than the ground, they still provide breeding areas for bacteria and fungus. Benches do not alleviate the problems of pot turnover unless the slat method is used. The problems with the slats, however, is that they do not allow versatility since they are constructed for one size container and the width is set and cannot be utilized for other widths of pots.
The stair-step system allows better use of growing area because of the utilization of vertical space. The disadvantage with the system is that there cannot be any overhang because of the light blockage and water run-off from the higher platforms. Some efficiency is achieved, but not enough to justify the tremendous costs of constructing the system. Again, the flat surfaces are problem areas for fungus and bacteria.
A search of the prior art in the patent office disclose the following patents: U.S. Pat. No. 1,063,961 (Dreyer, June 10, 1913), U.S. Pat. No. 1,001,416 (Lloyd, Aug. 22, 1911), U.S. Pat. No. 1,300,629 (Macaw, Apr. 15, 1911). The Dreyer and Lloyd patent are directed to display stands for flowers and are not suitable for use in nurseries or for the volume growing of plant material. The additional disadvantage of these two systems is that they are designed for a single width of flower pots and cannot be used for the various sizes of flower pots that are encountered in normal growing operations. U.S. Pat. No. 1,300,629 is similar to the slat system described herein above except that it provides for a variable width thus affording versatility in the size of pots that may be utilized. The disadvantage of this system is that it describes the use of a rigid rail for supporting the containerized plant material. The system described in the Macaw patent would today involve high cost both in manufacture and assembly and require upright supports every few feet, to prevent the rails from bending under their own weight.